The present invention is generally directed to a composition that stabilizes inorganic salts such as silicates and sulfates and, more particularly, to a composition and process for dispersing and suspending insoluble inorganic salts in fluids.
Scaling refers to a process by which insoluble particles contained within a fluid settle, accumulate and deposit on the surfaces of tanks, vessels, pipes and other equipment designed to contain the fluid. For instance, scaling can be a particularly troublesome problem in boilers and cooling towers. The water circulated in these systems can contain various insoluble inorganic salts, such as silicates, which can deposit on the boiler and cooling tube walls. Once deposited on a surface, the inorganic matter acts as an insulator, lowering the heat transfer coefficient and adversely affecting the ability of the boiler or cooling tower to transfer heat. The deposits can also interfere with the flow patterns of the fluids being circulated through the system.
Besides cooling towers and boiler applications, similar scaling problems can also occur in textile baths, such as bleach baths, in pulp and paper processes, in petroleum refinery processes and in other various processes. In these systems, besides silicate deposits, problems have also been experienced with other insoluble inorganic salts, such as sulfates.
Currently, in order to prevent against scaling, the water or other fluid containing the insoluble particulate matter is only allowed to remain in the system a certain number of cycles before being drained and replaced, for normally each cycle produces a greater build up of the unwanted insoluble particles. Clearly, a need exists for a chemical agent that can be added to fluids for preventing scaling.
One commercial prior art product, Acumer 5000 (Rohm and Haas), is available and is touted for suspending colloidal silica in water. However, when tried, it was found that the product only worked at a low pH where the silica products are soluble, and that the product did not perform at a pH around 7. The Acumer 5000 product is believed to be an acrylic.
In view of the problems associated with scaling, the present invention is directed to a composition that disperses and suspends insoluble inorganic matter within fluids to prevent the inorganic matter from settling and forming deposits on surfaces in contact with the fluid. The composition is particularly adapted to disperse and suspend insoluble silicates and sulfates contained within fluids.